For the first time, all 100 members of the chamber will have their own cloistered hideaways in the U.S. Capitol, traditionally a coveted mark of seniority and clout that lowly freshmen could only dream about.

This year, even junior senators will get their own private, unmarked offices that are a convenient few steps from the Senate chamber.

The addition of a dozen or so newly renovated rooms in the bowels of the Capitol represents a cultural shift in the custom-bound institution, made possible by moving a Capitol Police facility from the building's basement into the new, $621 million Capitol Visitor Center.

The vacated space inside the Capitol's West Front made room for even shunned members of the Senate — Illinois Democrat Roland Burris, for example — and freshmen minority Republicans to move in.

While both parties make claims and counterclaims about openness in government, some things never change. The first rule of Senate hideaways: Only senators talk about them. And then, selectively.

The only ways to know who occupies which office are to be invited, witness a senator entering or exiting or see a home-state newspaper outside the door in the morning. The hush-hush tradition creates sanctuaries for legislative work and meetings, as well as less official business — maybe even a nap.

Hideaways occupy nooks on all four floors of the historic building and are institutions within an institution and one of the last vestiges of nonpartisanship in an increasingly divided chamber. The most senior senators get first dibs, regardless of party.

They bear room numbers but no names. Some are hidden in plain sight, along corridors used by thousands of unknowing tourists. The portals to others hide beyond massive statues. Still others are crammed in the spaces around rotundas, or at the ends of hallways. Many can't be found without a guide.

Those occupied by such senior senators such as Robert Byrd, D-W.Va., and Patrick Leahy, D-Vt., tend to be grand affairs, with bathrooms, fireplaces, chandeliers and million-dollar views of the Washington and Lincoln memorials or the Supreme Court.

The newly renovated basement hideaways feature no such frills. These offices and some of their blueprints, examined by the Associated Press over the past year, reveal rooms that tend to be around 300 square feet, with low ceilings, no windows or bathrooms, and furnished with stock Senate tables and chairs.

No one will talk about how much the taxpayers are spending to create the new offices.

Discretion about hideaways is a courtesy senators expect of each other, one that some believe is more important than the public's right to know.

Rightly or wrongly, hideaways carry the image of unseemly privilege paid for by taxpayers. They have famously been used for business beyond the legislative sort, spaces "highly coveted by the powerful, and particularly by the playful," Bobby Baker, an aide to Sen. Lyndon B. Johnson, wrote in his book, Wheeling and Dealing: Confessions of a Capitol Hill Operator.

With three office buildings to house staffs for constituent services, and subways to shuttle senators virtually across the street for votes, no senator can claim to really need a hideaway.

But the desire for private office space inside the Capitol dates to the building's origins, when senators' offices were their desks on the chamber floor, according to Senate Historian Don Ritchie. Over the years, separate office buildings across the street went up to provide space for senators and their staffs to work.

As space in the Capitol became available, it was quietly awarded to senators by seniority. By early last year, the Rules Committee had found hideaways for as many as 90 senators, and none turned it down, said four officials familiar with the developments who demanded anonymity from the Associated Press because of the sensitivity of the issue.